Method for on-demand video editing at transcode-time in a video streaming system

ABSTRACT

A method includes: receiving a script configured to modify the audio-video file; calculating a performance metric based on execution of the script on a set of test files; classifying the script as performant based on the performance metric; defining a metadata store associated with the script and the audio-video file; receiving a playback request specifying a rendition of the audio-video file from a computational device; in response to receiving the playback request: accessing a set of data inputs from the metadata store; executing the script on a frame of the audio-video file based on the set of data inputs to generate a modified frame of the audio-video file; transcoding the modified frame of the audio-video file into the rendition to generate an output frame of the audio-video file; and transmitting the output frame of the audio-video file to the computational device for playback at the computational device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/905,230, filed on 24 Sep. 2019, which is incorporated in its entiretyby this reference.

This application is related to U.S. patent application Ser. No.16/458,630, filed on 1 Jul. 2019, which is incorporated in its entiretyby this reference.

TECHNICAL FIELD

This invention relates generally to the field of audio and video editingand more specifically to a new and useful method for on-demand videoediting at transcode-time in a video streaming system in the field ofaudio and video editing.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a flowchart representation of a method;

FIG. 2 is a flowchart representation of one variation of the method;

FIG. 3 is a flowchart representation of one variation of the method;

FIG. 4 is a flowchart representation of one variation of the method;

FIG. 5 is a flowchart representation of one variation of the method;

FIG. 6 is a flowchart representation of one variation of the method;

FIG. 7 is a flowchart representation of one variation of the method; and

FIGS. 8A and 8B are flowchart representations of the method.

DESCRIPTION OF THE EMBODIMENTS

The following description of embodiments of the invention is notintended to limit the invention to these embodiments but rather toenable a person skilled in the art to make and use this invention.Variations, configurations, implementations, example implementations,and examples described herein are optional and are not exclusive to thevariations, configurations, implementations, example implementations,and examples they describe. The invention described herein can includeany and all permutations of these variations, configurations,implementations, example implementations, and examples.

1. Method

As shown in FIG. 1, a method for transcode-time video editing includes:receiving a first script associated with a first audio-video file andconfigured to modify the first audio-video file in Block Silo;calculating a first value of a performance metric based on execution ofthe first script on a set of test files in Block S120; classifying thefirst script as performant based on the first value of the performancemetric in Block S130; defining a metadata store associated with thefirst script and the first audio-video file and configured to comprise aset of data inputs in Block S140; and receiving a first playback requestfor the first audio-video file from a first computational device, thefirst playback request specifying a first rendition of the firstaudio-video file in Block S150. The method S100 also includes, inresponse to classifying the first script as performant and in responseto receiving the first playback request: accessing the set of datainputs from the metadata store in Block S142; executing the first scripton a frame of the first audio-video file based on the set of data inputsto generate a first modified frame of the first audio-video file inBlock S160; transcoding the first modified frame of the firstaudio-video file into the first rendition to generate a first outputframe of the first audio-video file in Block S170; and transmitting thefirst output frame of the first audio-video file to the firstcomputational device for playback at the first computational device inBlock S180.

2. Applications

Generally, an audio-video streaming system (hereinafter “the system”),which can include a server and/or a computer network, can execute Blocksof the method S100 to: ingest a video editing script in association withan audio-video file (hereinafter “AV file”) or a live audio-video stream(hereinafter “livestream”); evaluate the ingested script to determinewhether the script can be executed just-in-time, during transcode of theaudio-video file (i.e. at “transcode-time”); and, in responseclassifying the script as a transcode-time eligible (i.e., performant)script (i.e., a “transcode-time script”), execute the script attranscode-time when serving a request for a rendition of the AV file inaccordance with an internet streaming protocol (e.g., HLS streaming).Therefore, by executing Blocks of the method S100, the system enablesusers to edit or modify an AV file that has already been uploaded to thesystem for streaming by simply submitting a new or updatedtranscode-time script associated with the AV file, as opposed to editinga local copy of the AV file and reuploading the AV file to the system.In a livestreaming application, the system can receive an updated scriptassociated with the livestream and modify graphics, filters, audio, orany other aspect of the livestream at the server side upon receipt andevaluation of the newly submitted script.

Thus, the system provides users with server-side resources to edit andmanipulate AV files before, during, or after the AV file is streamed toviewers of the AV file. Additionally, by modifying the AV file attranscode time, the system integrates updated visual and audio contentof the AV file into a stream-able encoding of the AV file, as opposed tosimply overlaying graphics and/or audio onto a separately transcoded AVfile. Thus, the system reduces the bandwidth occupied by the addition ofvisual or audio effects to the AV file and hampers extraction of theoriginal AV file from the modified AV file, thereby improving theefficacy of watermarks or other security-related effects added to an AVfile.

In addition to ingesting, evaluating, and executing transcode-timescripts on AV files and/or livestreams prior to streaming, the systemcan provide a scripting environment for transcode-time video editing andan API exposing various data elements of the AV file for manipulation bya transcode-time script, such as a video frame buffer, an audio framebuffer, raw pixel data of each frame in the video frame buffer, rawaudio data for each frame in the audio frame buffer, the time of the AVfile, total duration of the AV file, native resolution of the AV file,or any other data or metadata pertaining to the AV file. The system cansupport any common scripting language, such as JAVASCRIPT (e.g.,utilizing the CHROME V8 Engine), LUA, and PYTHON and can supportcorresponding APIs and/or libraries specific to video, audio, and imageediting, such as FFMPEG (for filters), HTML CANVAS (for graphics), orany other API or library. However, in addition to the languages, APIs,and libraries listed above, the system can support any interpreted orcompiled language and any API or library compatible therewith.Furthermore, the system can expose APIs with optimized and/or built-infunctions specific to transcode-time AV editing in order to improve auser's scripting experience within the scripting environment.

In order to execute video, audio, or image editing scripts on-demand andat transcode-time, the system leverages just-in-time transcodingtechnology described in related U.S. patent application Ser. No.16/458,630, which is incorporated in its entirety by this reference.Therefore, the system can execute just-in-time transcoding to accumulatea full set of transcoded rendition segments for an AV file, wherein eachrendition segment is transcoded in (near) real-time following a firstrequest for this rendition segment from an AV player instanceafter—rather than before—the AV file is published for streaming. Thus,the computer system can greatly reduce the time-to-publication of an AVfile. Additionally, the computer system can reduce the immediatecomputational requirements for transcoding an AV file into a number ofadvertised renditions in a short period of time (i.e. before publishingthe stream of the AV file) and can instead spread this computationalload over a longer period of time. Furthermore, by transcoding renditionsegments of the AV file on-demand, the computer system can conservestorage space for the time period before each rendition segment isrequested for the first time. Therefore, the system executes Blocks ofthe method S100 before, during, and/or after executing steps of thejust-in-time transcoding process. As a result, the system can execute atranscode-time script associated with an AV file when that AV file isrequested for streaming, thereby conserving computational editingresources if the AV file is not requested for viewing. For example, ifthe system ingests an AV file and an associated transcode-time scriptconfigured to render a graphical overlay in the AV file, the system canexecute this transcode-time script upon receiving a request to stream aparticular segment and can render the graphical overlay for the segmentthat is streamed to a viewer. Therefore, if other segments of the AVfile are never requested, the system saves the computational time thatwould have been required to render the graphical overlay in thosesegments.

The system can ingest a transcode-time script alone (e.g., inassociation with a previously ingested AV file) or paired with anassociated AV file. Upon ingesting a script, the system can perform aset of tests to evaluate the performance characteristics of thetranscode-time script (e.g., according to a performance metric).Therefore, the system can execute the transcode-time script on a seriesof test AV files to identify whether the script exceeds any of a set ofruntime thresholds, whether the transcode-time script modifies audiodata, video data, or both types of data, and/or the ideal hardware forexecuting the transcode-time script (e.g., a server equipped with aGPU). Once the system has evaluated the transcode-time script, thesystem can classify the transcode-time script as either a performant(i.e., approved for execution at transcode-time) or a non-performantscript (i.e., an ingest-time script, a script to be executed at ingesttime). If the system classifies a transcode-time script asnon-performant, then the system can execute the script at ingest time onthe mezzanine version of the AV file. Alternatively, if the systemclassifies the transcode-time script as performant script, the systemcan store the script for execution at transcode-time.

In one implementation, the system can define a metadata store associatedwith a transcode-time script to store metadata to be utilized by thetranscode-time script. The system can also receive metadata scripts,which the system can execute in order to push data inputs to thetranscode-time script to the metadata store associated with thetranscode time script. For example, the system can periodically (e.g.,every minute) execute a metadata script to push (i.e. store) a currentstock price to the metadata store. Therefore, upon receiving a playbackrequest for the AV file, the system can access the current stock price,and render an overlay image in the AV file prior to transcoding the AVfile into the requested rendition. The system can, therefore, define anAPI to append, access, and/or format data in a metadata store associatedwith a transcode-time script in order to enable a user to view or modifythe content of the metadata store (and therefore any relatedfunctionality of the transcode-time script). Alternatively, the systemcan receive and execute an ingest-time metadata script, to generate datainputs for a transcode-time script by extracting these data inputs in afirst pass of the AV file at ingest time. For example, the system canexecute a computationally expensive ingest-time metadata script thatidentifies the pixel location and/or orientation of faces detected ineach frame of the AV file and stores these pixel locations and/ororientations in the metadata store associated with a correspondingtranscode-time script. Therefore, when the system executes thetranscode-time script on the AV file at transcode time, the system canaccess the stored pixel locations and/or orientations in order to modifythe AV file based on the locations and/or orientations of faces withinthe AV file, a process that may otherwise be prohibitivelycomputationally expensive to execute at transcode-time.

In another implementation, the system can execute a data collectiontranscode-time script in order to record data based on the contents ofan AV file. For example, the system can execute a script that classifiesobjects within a livestream and saves a classification vector to themetadata store, such that a user can later analyze these vectors todetermine the content of the livestream. Thus, the system can enabledata collection (e.g., for a livestream) in the metadata store.

Once the system classifies the script as a performant transcode-timescript and defines a metadata store for the script, the system can, inresponse to receiving a request to view the AV file associated with thescript, execute the transcode-time script on the mezzanine version ofthe AV file, transcode the modified AV file to a requested rendition,and serve (e.g., transmit or stream) the modified and transcoded videoto a viewer or other requesting entity such as content delivery network(hereinafter “CDN”). Thus, the system provides flexible, server-sidevideo and audio editing capabilities to users while minimizing increasesin latency and computational load associated therewith.

3. Terms

Generally, the term “stream,” as used herein, refers to a bitstream ofencoded audio, video, or any other data between two devices orcomputational entities executing on devices (e.g., AV players executingon a mobile computing devices) such as an HLS, HDS, or MPEG-DASH stream.Therefore, the system can initiate streams between servers in thesystem, between the system and a content delivery network (hereinafter“a CDN”), or between the system and any other computational device.

Generally, the term “segment,” as used herein, refers to a series ofencoded audio and/or encoded video data corresponding to a particulartime interval or consecutive series of frames in an AV file or AVstream.

Generally, the term “mezzanine,” as used herein, refers to the highestquality (e.g., high bitrate and high resolution) encoding (i.e. abitrate resolution pair) of an AV file cached by the system that derivesfrom the original version of the AV file uploaded to the system.Therefore, a “mezzanine segment” refers to a segment of an AV fileencoded at the highest quality encoding for the AV file.

Generally, the term “rendition” refers to any encoding of an AV filethat is indicated in the rendition manifest or manifest file (e.g., anHLS manifest) associated with a stream of the AV file. Therefore, a“rendition segment” refers to a segment of the AV file that has beentranscoded at a bitrate and/or resolution different from the mezzaninesegment. The system can transcode any mezzanine segment into multiplecorresponding rendition segments in various renditions representing thesame time interval in the AV file at differing bitrates and resolutions.

Generally, the term “playback segment” refers to a segment requested bya CDN or directly from an AV player specifying a time interval in the AVfile and a rendition of the AV file to be served by the system.Therefore, a playback segment coincides or is coincident with amezzanine segment or rendition segment if a time interval defined by theplayback segment temporally overlaps with the mezzanine segment orrendition segment in the AV file respectively. Additionally oralternatively, the AV player or CDN can request a playback segment byspecifying an index (e.g., a segment number) of a total number ofplayback segments in the AV file (e.g., based on a playback segmentduration). Therefore, the system can calculate a playback interval by inthe AV file based on the index of the requested playback segment and aknown (or specified) playback segment duration (e.g., 5 seconds).

Generally, the term “transcode-time script” refers to a script (e.g., aset of computer instructions) received by the system for execution attranscode time. However, the system can classify a transcode-time scriptas non-performant and instead execute the transcode-time script atingest time or opt not to execute the transcode-time script at all.

Generally, the term “ingest-time script” refers to a script received bythe system for execution at ingest time or shortly after an associatedAV file is uploaded to the system. Thus, the system can execute aningest-time script on an AV file independent of receiving a playbackrequest for an associated AV file.

Generally, the term “metadata script” refers to a script received by thesystem to update or otherwise modify data inputs to a transcode-timescript within a metadata store associated with the transcode-timescript. Thus, the system can execute a metadata script to maintain anupdated set of data inputs in the metadata store and thereby incorporatethis set of data inputs into the AV file at transcode time according toan associated transcode-time script.

Generally, the term “performant” indicates that the system hasdesignated that a transcode-time script can be executed attranscode-time without noticeably affecting stream latency and/or streamquality of an associated AV file.

Generally, the term “non-performant” indicates that the system hasdesignated that a transcode-time cannot be executed at transcode timewithout noticeably affecting stream latency and/or stream quality of anassociated AV file.

Generally, the system can execute a script “on” an AV file to modify orextract data from: individual or multiple video frames, individual ormultiple audio frames, audio and/or video header data, or any other datawithin an AV file.

Generally, the system can interface directly with an AV player instanceon a local computing device. Alternatively, the system can serve astream of the AV file to a content delivery network (hereinafter “CDN”),which can relay the stream of the AV file to the AV player instance. Forease of explanation, any discussion herein of requests by an AV playerinstance are also applicable to requests by CDNs.

4. Scripting Environment

The system can host a scripting environment in the form of anapplication configured to interface with the system and improve userexperience when writing scripts for on-demand video editing. Thescripting environment can define a graphical user interface for writingscripts for transcript-time execution according to the method S100. Thescripting environment can include features configured to assist users inwriting scripts compliant with the method S100.

In one implementation, the scripting environment can support syntaxhighlighting for audio and/or video frame buffer primitives andsupported or built-in functions for common AV file modifications (e.g.,color filters, simple graphics). Additionally, the scripting environmentcan provide debugging features to highlight particular lines of code,such as loops and conditionals, which may cause incompatibilities (e.g.,greater than threshold runtimes) during execution of Blocks of themethod S1 oo. Furthermore, the scripting environment can prohibit usageof certain networking functionality of each supported scripting languagein scripts written in the scripting environment.

However, the system can also ingest scripts written in any standardprogramming environment.

4.1 Exposed AV Elements

The system can provide an API for interfacing with AV files ingested bythe system, which can define primitives for accessing audio and videoframe buffers, pixel data for each video frame, audio spectrum data foreach audio frame, total AV file duration, current AV file time, AV fileresolution, other video compression data for a compressed mezzanine AVfiles. Additionally, the system can define primitives for accessing data(e.g., appending or dequeuing) from a metadata cache associated with theAV file, which is further described below.

4.2 Scripting Examples

Although the system can execute any script while transcoding an ingestedAV file, the following section includes examples illustrative of thecapabilities of the system.

In one example, the system can execute a script on an AV file thatstrips color from each video frame of the AV file such that the videostreamed to the user is black and white despite the originally ingestedAV file including colored pixels. Thus, the system can execute scriptsthat selectively change color values of pixels in an AV file. Therefore,a user of the system may apply filters to previously or concurrentlyingested AV files post hoc to, for example, designate particular contentas outdated content (e.g., via a black and white filter) or to improvethe brightness in an AV file following feedback the that AV file is toodark by uploading a script as opposed to an entirely new AV file.

In another example, the system can execute a script on an AV file thatrenders a graphic within each video frame of the AV file such that thevideo streamed to the user includes the rendered graphic despite theoriginally ingested AV file not including the same graphic. Thus, thesystem can execute scripts that generate graphics, watermarks, or anyother additive visual content. Therefore, a user of the system can, forexample, apply subtitles, user specific watermarks, or other visuals topreviously or concurrently ingested AV files.

In yet another example, the system can execute a script on an AV filethat renders a graphic within each video frame of the AV filerepresenting the concurrent audio frame of the AV file (e.g., as awaveform). Thus, the system can execute scripts that interact with bothaudio and video data of an AV file. Therefore, a user of the system can,for example, modify the volume of the AV file or render visuals based onthe audio component of the AV file (e.g., speech detection-basedsubtitles) on previously or concurrently ingested AV files.

In yet another example, the system can execute a script on an AV filethat renders a graphic within each video frame of the AV filerepresenting a stock price (or any other data element stored in ametadata store associated with the AV file) that has been appended tometadata associated with the script and the AV file. Thus, the systemcan execute scripts that modify the AV file based on metadata stored ina metadata store associated with the AV file. Therefore, a user of thesystem can update graphics or information presented in a previously orconcurrently ingested AV file in real-time.

In yet another example, the system can execute a script on a livestreamthat performs object recognition on incoming video frames of thelivestream and counts the number of cars detected in video frames of thelivestream. Thus, the system can execute scripts that analyze frames ofan AV file (or livestream) and can store metadata in a metadata storeassociated with the AV file.

5. AV File and Script Ingest

As shown in FIG. 1, in Block S110, the system can store a transcode-timescript associated with an AV file in a script store. More specifically,the system can ingest a new transcode-time script and a new AV fileconcurrently or in succession. For example, the system can ingest a newtranscode-time script in association with a preexisting AV file or caningest a new AV file in association with a preexisting transcode-timescript. Additionally, the system can ingest new scripts (i.e.,transcode-time scripts, ingest-time scripts, and/or metadata scripts)associated with a class of AV files. For example, the system canassociate a new script with a set of AV files from the same publisher orother entity.

Upon receipt of a new transcode-time script for ingest, the system can:classify the transcode-time script as a performant or non-performantbased on a test set of AV files; perform an initial transcode ortransmux on the ingested AV file in order to normalize the encoding ofthe AV file; define a metadata store associated with the combination ofthe ingested transcode-time script and the associated AV file; executeany ingest-time scripts during initial transcode or transmux of theingested AV file; store any transcode-time scripts for later execution;and assign a unique URL corresponding to the combination of the ingestedtranscode-time script and the associated AV file. Additionally, whenstoring a newly ingested AV file, the system can segment (e.g., at eachkeyframe of the AV file) and store the AV file in a mezzanine cache.

In addition to ingesting a transcode-time script, the system can alsoingest ingest-time scripts, metadata scripts, and/or ingest-timemetadata scripts in association with a concurrently received AV file ora preexisting AV file. Upon ingesting an ingest-time script, the systemcan successively execute the ingest time script on the associated AVfile and reencode the mezzanine version of the AV file prior to storingthe AV file in a mezzanine cache. Thus, the system can executecomputationally expensive scripts prior to transcode time in order toprevent an increase in latency and/or a reduction in quality of thestream of the AV file.

Upon ingesting a metadata script, the system can identify whether themetadata script is designated as an ingest-time metadata script or aperiodic metadata script. In response to identifying the metadata scriptas an ingest-time metadata script the system can execute the script onthe associated AV file at ingest-time and store data generated by theingest-time metadata script to the metadata store associated with thetranscode-time script and/or the AV file. In response to identifying themetadata script as a periodic metadata script, the system can store theperiodic metadata script and can repeatedly execute the periodicmetadata script according to a time interval specified by the periodicmetadata script in order to update data inputs stored in the metadatastore associated with the transcode-time script and/or the AV file.

5.1 Mezzanine Segments

Generally, the system can ingest a new AV file and segment the AV fileinto a set of mezzanine segments for subsequent just-in-time transcodingbased on the location of keyframes in the AV file, as described in U.S.patent application Ser. No. 16/458,630. More specifically, the systemcan: normalize the encoding and container format of the AV file;identify keyframes in the AV file; and segment the AV file into a set ofmezzanine segments based on the identified keyframes in the AV file.Thus, the system prepares the AV file for just-in-time transcoding andmodification via execution of a transcode-time script.

5.2 Transcode-Time Script Classification

As shown in FIG. 2, the system can calculate a first value of aperformance metric based on execution of a transcode-time script on aset of test files, in Block S120, and classify the transcode time scriptas performant or non-performant, in Block S130, in order to evaluatewhether the system can execute the transcode-time script during thetranscoding process without substantially increasing latency orbandwidth required to stream the AV file. More specifically, the systemcan: select and access a set of test files representative of the AV fileassociated with the transcode-time script; execute the transcode-timescript on each test file in the set of test files (or a sampling offrames from each test file in the set of test files); and calculate aperformance metric based on the execution of the transcode-time scripton the set of test files. Thus, the system can more accurately detectnon-performant transcode-time scripts that cannot be executed attranscode-time due to computational or latency concerns.

The system can execute the foregoing Blocks of the method S100 on astandardized test set of AV files in order to evaluate the performanceof ingested scripts on a range of possible input AV files. Morespecifically, the standardized test set of files can include AV files(or still images) spanning a range of visual/audio complexities,durations, framerates, resolutions, bitrates, encoding, containerformat, or any other characteristic of an AV file. In oneimplementation, the system can execute the script on a test set of fileswith the same resolution(s), bitrate(s), encoding, and/or containerformat that the system can offer for streaming of the AV file associatedwith the script.

In one implementation, by selecting a set of similar test files, thesystem can reduce the probability of misclassification of thetranscode-time script, thereby improving overall system reliabilitywhile still offering substantial flexibility to users in writing fullycustom transcode-time scripts. In one implementation, the system canexecute a video classification model (e.g., a machine learning model) tocharacterize the content, visual properties, and/or audio properties ofthe AV file associated with the transcode-time script by generating aclassification vector representing the AV file associated with thetranscode-time script. The system can then compare (e.g., by calculatinga difference vector) the classification vector characterizing the AVfile associated with the transcode time script with a precalculatedclassification vector characterizing each test file in a set of testfiles. The system can then select a subset of most similar test files byselecting test files with low difference vectors based on theclassification vector characterizing the AV file. Thus, the system can:select a set of similar test files to the first AV file based on the AVfile and a video classification model; and calculate the first value ofthe performance metric based on execution of the first script on the setof similar test files.

Additionally or alternatively, the system can select a set of previousAV files submitted to the system, by the same publisher as the currentAV file, as test files for the purpose of classifying the transcode-timescript associated with the AV file. Thus, the system can: select a setof similar test files to the AV file based on a prior set of filessharing a publisher with the AV file; and calculating the first value ofthe performance metric based on execution of the first script on the setof similar test files. Furthermore, the system can execute a combinationof the aforementioned test file selection processes and select a subsetof similar test files from a set of AV files previously submitted by thepublisher of the current AV file.

The system can also define subsets of the set of test files thatevaluate specific performance features of the transcode-time script. Forexample, the system can define a subset of the test set that have a highvisual complexity and a subset of the test set that have a high audiocomplexity.

Additionally or alternatively, the system can generate a custom test setbased on an AV file associated with the script. In one implementation,the system can generate a custom test AV file based on a set of framesof the AV file associated with the script. In yet another alternativeimplementation, the system can provide an interface for the user todefine a custom test set of AV files with which the system can evaluatefuture scripts written by the user.

However, the system can store and/or generate a test set of files in anyother way.

Upon executing the transcode-time script on the set of test files, thesystem can calculate a performance metric in order to classify thetranscode-time script. In particular, the system can calculateindividual values of a performance metric for each execution of thetranscode-time script on a test file and aggregate these values via asummary statistic in order to calculate a value for the performancemetric. The system can calculate performance metrics including scriptruntime, script memory usage, and/or script power consumption and canaggregate these via summary statistics including average, weightedaverage, median, or mode. Alternatively, the system can generate aperformance metric for each test file and classify whether thetranscode-time script is performant for each individual test file. Thesystem can then classify the transcode-time script based on theproportion of “passes” relative to a threshold value indicating aminimum value of the performance metric for each test file.

In one implementation, the system can: execute the transcode-time scripton the set of test files to generate a set of runtimes; and, in responseto a first threshold runtime exceeding each of the set of runtimes,classify the transcode-time script as a performant transcode-timescript. More specifically, the system can execute the transcode-timescript on a set of preexisting test files and record one or moreruntimes for each test file in the set of test files in order toevaluate the performance of the transcode-time script on a range of AVfiles.

In another implementation, the system can execute the transcode-timescript on test files using different hardware in order to evaluate theperformance of the transcode-time script when executed by varioushardware available to the system. For example, the system can executethe transcode-time script on a subset of test files at a first machineincluding a central processing unit (hereinafter “CPU”) and also executethe transcode-time script on the same subset of test files at a secondmachine including a graphics processing unit (hereinafter “GPU”).Therefore, the system can record two runtimes (corresponding to thefirst and second machine) for one test file.

After recording the set of runtimes, the system can compare the set ofruntimes to a set of runtime thresholds in order to classify thetranscode-time script as a non-performant transcode-time script (forexecution at ingest time) or a performant transcode-time script. In oneimplementation, the system can classify the transcode-time script as aperformant transcode-time script if all of the set of runtime thresholdsexceed the corresponding runtimes recorded for the transcode-time scriptwhen executed on the set of test files. In another implementation, thesystem can classify the transcode-time script as a performanttranscode-time script if a threshold proportion of runtime thresholdsexceed the corresponding runtime for the set of test files. In yetanother implementation, the system can classify the transcode-timescript as a performant transcode-time script if an average runtime ofthe set of runtimes is less than a threshold runtime. Additionally oralternatively, the system can calculate a weighted average runtime andclassify the transcode-time script as a performant transcode-time scriptif the weighted average runtime is less than a threshold runtime.

However, the system can execute any other type of statisticalclassification on the set of performance metric values in order toclassify the transcode-time script as a performant transcode-time scriptor a non-performant transcode-time script.

In one implementation, the system can classify a transcode-time scriptas performant on specific hardware based on the set of runtimes recordedfrom executing the transcode-time script on test files at specifichardware available to the system. For example, the system can classifythe transcode-time script as a performant transcode-time script whenexecuted on hardware including a GPU and a non-performant transcode-timescript when executed on hardware not including a GPU, and, in response,select hardware including a GPU for execution of the transcode-timescript on the AV file.

In one implementation, the system can designate a transcode-time scriptas a non-compliant transcode-time script if the transcode-time scriptfails to compile or does not return a compliant output within apredetermined time period. If the system does not classify atranscode-time script as a performant transcode-time script and does notdesignate the transcode-time script as a non-compliant transcode-timescript, the system can classify the transcode-time script as anon-performant transcode-time script for execution during ingest-time ofthe AV file and/or during transcoding of the mezzanine segments of theAV file.

5.3 Transcode-Time Script

Upon classifying a transcode-time script as performant, the system canstore the transcode-time script in association with the AV file forlater execution by the system during the just-in-time transcodingprocess. Therefore, the system can conserve computational resources forexecuting the script on the AV file when the AV file is requested by aplayer instance or CDN.

5.4 Metadata Store

Upon receiving a transcode-time script or an AV file, the system candefine a metadata store associated with the transcode-time script and/orthe corresponding AV file. More specifically, the system can define ametadata store associated with the transcode-time script and the AV fileand configured to store a set of data inputs in Block S140. Thus, whileexecuting a transcode-time script on the AV file, the system can accessa set of data inputs informing the modifications to the AV fileperformed by the system according to the transcode-time script.

The system can define application programming interfaces (hereinafter“APIs”) to interface with the metadata store for inclusion intranscode-time scripts, ingest-time scripts, and metadata scripts. Forexample, the system can define APIs that enable the creation or updateof data variables in a metadata store associated with a given AV fileand associated with a given transcode-time script. Additionally oralternatively, the system can define an API that accesses a set ofexisting data inputs stored in a given metadata store.

In one implementation, the system defines a metadata store that isappended only for a user. Therefore, the user (via a script) can appendmetadata to the metadata store. The system, when executing atranscode-time script, can then access the most recently appended datafor user by the transcode-time script.

Additionally or alternatively, the metadata store can function as acache for metadata accumulated by a transcode-time script. The systemcan serve the metadata store to a user for review of the cachedmetadata.

5.5 Ingest-Time Scripts

During and/or after normalization of an ingested AV file, the system canexecute a ingest-time script associated with the AV file (or anynon-performant transcode-time scripts associated with the AV file).Therefore, the system can classify a script as a non-performanttranscode-time script and instead execute the transcode-time script onthe AV file during ingest of the AV file.

Alternatively, as shown in FIG. 3, the system can receive a scriptdesignated by a user as a ingest-time script and can execute thedesignated ingest-time script during normalization of the AV fileindependent of any classification of the transcode-time script. Thesystem can therefore provide a user the opportunity to generate metadatato be utilized by a transcode-time script in a metadata store associatedwith the AV file.

Therefore, the system can: execute ingest-time scripts that generate andstore metadata about the AV file; and execute a correspondingtranscode-time script that can then access these metadata instead ofgenerating the metadata at transcode-time in order to perform morecomplex or state dependent functions. More specifically, the system can:receive a transcode-time script associated with an AV file; and receivean ingest-time script associated with the same AV file, associated withthe transcode time script, and configured to generate a set of datainputs for the transcode-time script based on the AV file. The systemcan then, at ingest time of the AV file: execute the ingest-time scripton the AV file to generate the set of data inputs for the transcode-timescript; and store the set of data inputs in the metadata storeassociated with the transcode-time script. Thus, at transcode-time, thesystem can execute the transcode-time script based on the set of datainputs stored in the metadata store.

In one example, the system can execute an ingest-time script to extractpixel locations and orientations of facial features for frames of the AVfile, as the set of data inputs, in order to reduce latency at transcodetime when the system can execute a transcode-time script to add facialgraphics (e.g., filters) to the AV file based on the extracted pixellocations of facial features.

In another example, the system can execute an ingest-time script toextract audio amplitude data from the AV file prior to transcode-timeand store the extracted audio amplitude data in the metadata store. Thesystem can, subsequently, execute a transcode-time script to normalizethe volume of the AV file based on the extracted audio amplitude datastored in metadata store. Thus, the system can extract datacharacterizing the full length of the AV file at ingest time while onlyexecuting the transcode-time script on requested segments of the AVfile.

In yet another example, the system can execute an ingest-time script ona livestream in order to characterize the content of the livestream andstore these metrics in the metadata store associated with thelivestream. The system can then enable access to these metrics forfurther analysis.

5.6 Periodic or Conditional Metadata Scripts

Upon completion of the above-described ingest process, the system can,as shown in FIG. 4, execute periodic metadata scripts or conditionalmetadata scripts in order to update the metadata store associated withan AV file with real-time data in response to a periodic timer or inresponse to detecting particular conditions. More specifically, thesystem can: receive a metadata script associated with the AV file andthe transcode-time script and configured to update the set of datainputs based on a third-party data source; and after ingest time of theAV file, periodically, execute the metadata script to retrieve newvalues for the set of data inputs from the third-party data source andupdating the set of data inputs in the metadata store to generate anupdated set of data inputs based on the new values for the set of datainputs. Thus, the system can execute a metadata script to push updatedvalues of the set of data inputs for use by the system in execution ofthe associated transcode-time script.

In one implementation, the system can execute a metadata script toperiodically push (i.e. according to a predetermined time interval) newvalues of a set of data inputs from a third-party source to a metadatastore. For example, the system can periodically (e.g., every minute,every hour, every 24 hours) push a set of updated data inputsrepresenting the current weather to the metadata store associated withthe AV file via a metadata script associated with an AV file depicting aweather forecast. In this example, the system can then execute atranscode-time script that generates updated weather graphics within theAV file based on the current set of data inputs representing weatherdata stored in the metadata store.

In another implementation, the system can execute a metadata script topush new values of a set of data inputs from a third-party source to ametadata store based on a set of trigger conditions. For example, thesystem can execute a metadata script that pushes new values of a gamescore to the metadata store in response to a score occurring in a sportsgame (or other game). The system, upon executing the transcode-timescript, can then update a graphic representing the live score of thegame in the AV file and serve the updated AV file to a user device.Thus, the system can execute metadata scripts that push data inputs forthe AV file to the metadata store in response to real-time events.

5.7 Livestream Ingest

The system can ingest an AV livestream in a similar manner to an AVfile. The system can: normalize an incoming livestream; segment thelivestream according to keyframes identified in the livestream; andstore mezzanine segments of the livestream in a mezzanine cache for thelivestream. The system can also associate one or more transcode-timescripts with the livestream for execution upon just-in-time transcodingof the livestream mezzanine segments into streamed rendition segments.The above-described process is further described in in U.S. patentapplication Ser. No. 16/458,630.

5.8 Playback IDs and URLs

Generally, the system can assign a URL to a combination of scripts(transcode-time scripts, ingest time scripts, and/or metadata scripts)and an AV file. More specifically, the system can assign a universallyunique identifier (hereinafter a “playback ID”) to each unique pair ofan AV file (or a livestream) and an associated script; and generate aURL for the pair of the AV file and the associated script based on theplayback ID. The system can then provide a stream of the AV file,modified by the script, based on requests received at the specified URL.Additionally, the system can maintain a separate mezzanine cache and/orrendition cache for each URL assigned by the system.

In one implementation, the system can generate unique URLs andcorresponding distinct rendition caches for various combinations oftranscode-time scripts, ingest-time scripts, and/or metadata scripts.For example, the system can generate a first playback ID andcorresponding first URL representing the combination of a first AV fileand a first transcode-time script. Upon receiving a secondtranscode-time script in replacement of the first transcode-time script,the system can generate a second playback ID and a corresponding secondURL representing the combination of the first AV file and the secondtranscode-time script. Upon receiving a first ingest-time script to beexecuted in addition to the transcode time script, the system cangenerate a third playback ID and a corresponding third URL representingthe combination of the first AV file, the second transcode-time script,and the first ingest-time script. Thus, the system can generate a newplayback ID to represent any new combination of scripts and the AV file.

6. Playback Requests

Generally, upon ingesting a transcode-time script and an AV fileaccording to the above-described Blocks of the method S100, the systemcan publish a stream of the AV file to AV player instances executing oncomputational devices (e.g., smartphones, tablet computers, laptopcomputers, desktop computers) by generating a manifest file advertisinga set of available renditions of the AV file to the AV player instances.The system can then receive a request from an AV player instance (e.g.,via a CDN) for a particular rendition of the AV file in order to renderthe AV file at the AV player instance. More specifically, the system canreceive a playback request for an AV file from a computational device,the playback request specifying: a playback segment of the AV file; aspecific rendition of the AV file; and/or the associated transcode-timescript of the AV file, via a unique URL associated with the combinationof the AV file and the associated transcode-time script in Block S150.Thus, the system can, in response to receiving the playback, requestinitiate execution of the transcode-time script and transcoding of theAV file modified by the script.

6.1 Rendition Cache Generation

Generally, the system can define a set of rendition caches associatedwith a playback ID (and therefore a combination of scripts and the AVfile), wherein each rendition cache in the set of rendition cachescorresponds to a particular bitrate resolution pair for which the AVfile is available for streaming. However, if a new transcode-time scriptis ingested in association with an existing AV file or a data input tothe transcode-time script is modified such that, upon execution of thetranscode-time script, the AV file changes relative to a previousversion of the AV file (e.g., that was modified according to a priortranscode-time script), the system can generate a new rendition cache inwhich to store newly modified and transcoded segments of the AV file.

Thus, upon modifying and transcoding mezzanine segments of the AV filecorresponding to requested playback segments of the AV file intorendition segments in the requested rendition, the system can store theresulting modified rendition segments into a rendition cachecorresponding to the combination of the transcode-time script and the AVfile. The system can define a rendition cache for each uniquecombination of script and AV file. Therefore, if the system ingestsmultiple scripts in association with a single AV file, then the systemcan define a rendition cache for each script.

In implementations wherein the system assigns URLs including URL fields,the system can define a new rendition cache corresponding to each uniquestring received as a URL parameter even if the transcode-time script andAV file corresponding to the URL have remained the same. Thus, thesystem can define separate rendition caches for each unique version ofthe AV file produced by a single script.

6.1.1 URL Parameters

In one implementation, as shown in FIG. 5, the system can generate URLsincluding URL parameter fields within which the computational deviceexecuting an AV player instance (e.g., via a browser applicationexecuting the AV player instance) can inject particular strings forutilization by the system in an associated transcode-time script. Morespecifically, the system can: extract a URL parameter value from the URLparameter field; and execute the transcode-time script on a frame of theAV file based on the set of data inputs and the URL parameter value togenerate a modified frame of the AV file.

In one example, for a transcode-time script that generates a graphicdisplaying a name within the video (e.g., a happy birthday graphic in ahappy birthday video, a watermark indicating the viewer of the video),the system can generate a URL with a field for specifying the name inthe graphic. Upon receiving a string via the URL field, the system cangenerate a separate rendition cache if the string in the URL field is anew string or can access a previously existing rendition cache inresponse to receiving a request URL with the same string in the URLfield. In another such example, the system can render a watermarkrepresenting a URL parameter value over frames of the first audio-videofile to generate modified frames of the first audio-video file includingthe watermark. Thus, if a viewer attempts to redistribute the AV file,the original viewer responsible for this redistribution can be easilyidentified.

In yet another example, the system can generate a URL field within whichthe computational device executing the AV player instance can insert thecurrent location of the computational device. The system can then, uponreceiving a request at the URL including the URL field, execute alocation-dependent transcode-time script based on the current locationextracted from the URL field. Thus, the system can modify frames of theAV file with location-dependent graphics or other effects such as localweather, local news tickers, or any other graphic.

Additionally, the system can execute a URL signing protocol to preventabuse of the URL fields to generate an unlimited number of renditioncaches via repeated requests at URLs with different strings in a URLinput field.

6.1.2 Saved State Cache

Because the system can execute metadata scripts that update data inputsfor the transcode-time script in real-time, the system can generatedifferent versions (e.g., based on a different set of data inputs to thetranscode-time script) in response to receiving playback requests forthe AV file at different times. In one example, the system can execute atranscode-time script that renders the current time within each frame ofthe AV file. In this example, if the system receives a first playbackrequest for a first segment (or rendition) of the AV file at a firsttime, the system executes the transcode-time script to render the firsttime into each frame of the first segment (or rendition) of the AV file.If the system later receives a second playback request for a secondsegment of the AV file at a second time, the system executes thetranscode-time script to render the second time into each frame of thesecond segment. The system can then store each of these segments in therendition cache and, in response to receiving a playback request foreither of the first or second segment, the system can serve thesesegments directly from the rendition cache (instead of modifying andtranscoding these segments again)

Thus, in this example, the system renders a time into the AV file thatis not representative of the time at which a viewer is viewing the AVfile or representative of the time at which the video was first streamedor uploaded. Instead, the system renders a time that corresponds to thetime at which each segment (or rendition) was first transcoded.

This effect may be counterintuitive and/or confusing to viewers of theAV file and, therefore, the system can mitigate these effects by savingthe state of the metadata cache at a time when the AV file is firstrequested. Thus, the system can modify the AV file according to a staticset of data inputs from the metadata file after a first viewing of theAV file, thereby ensuring that each subsequent view of the AV fileincludes temporally consistent graphics and/or audio effects across theentire AV file. More specifically, the system can: in response toreceiving a first playback request for the AV file, save the state ofthe metadata store corresponding to the AV file and the transcode-timescript; and, in response to receiving a second playback request of theAV file, execute the transcode-time script based on the saved state ofthe metadata store.

In one implementation, as shown in FIG. 6, the system can save the stateof the metadata store for a predetermined time interval during whichtime the set of data inputs to the transcode-time script remain static.In response to expiration of the predetermined time interval, the systemcan define a new rendition cache and enable a metadata script to updatethe metadata store with a new set of data inputs. Upon receiving,another playback request, the system can again save the state of themetadata store for the predetermined time interval. In this manner, thesystem can ensure version consistency within each time interval, whileallowing variation in the AV file over time in accordance with changesto the data inputs of the transcode-time script within the metadatastore.

In another implementation, as shown in FIG. 7, the system can save thestate of the metadata store until a set of conditions are satisfied. Forexample, the system can maintain the state of the metadata store until agoal is scored in a live sports game. In response, the system can thenenable a metadata script to update the metadata store to reflect thischange in the score. Thus, via the above-described hybrid approach, thesystem can maintain real-time responsiveness to changes in input datawithout creating inconsistencies between prior versions of the AV fileand current versions of the AV file. One disadvantage of this approachis the increased computational cost and storage cost incurred by thesystem when defining a new rendition cache for each version of the AVfile and when re-executing and re-transcoding the AV file for each newversion of the AV file. However, the system, upon updating the state ofthe metadata store, can delete prior versions of the AV file stored inrendition caches in order to reduce storage costs.

7. Just-in-Time AV Editing

After storing the AV file in a mezzanine cache, defining a renditioncache, defining a metadata store associated with AV file, and storingthe transcode-time script for later execution, the system can, inresponse to receiving a playback request for the AV file, just-in-timemodify the AV file according to the transcode-time script andjust-in-time transcode the modified AV file before transmitting the AVfile to a requesting computational device. More specifically, the systemcan: access a set of data inputs from the metadata store in Block S142;execute the transcode-time script on a frame of the AV file based on theset of data inputs to generate a modified frame of the AV file in BlockS160; transcode the modified frame of the AV file into a first renditionto generate an output frame of the AV file in Block S170; and transmitthe output frame of the AV file to the requesting computational devicefor playback at the requesting computational device in Block S180. Thus,by only executing the transcode-time script and, therefore, modifyingframes of the AV file in response to a playback request, the system canreduce computational costs at ingest-time by only executing thetranscode-time script on requested segments of the AV file. As a result,if particular segments of the AV file are never requested, the systemconserves the computational costs of running the transcode-time scripton these particular segments.

In order to execute the transcode-time script and transcode coincidentmezzanine segments into rendition segments, the system can identify aset of mezzanine segments that correspond to the requested playbacksegment. More specifically, once the system receives the request for aplayback segment, the system identifies a consecutive subset ofmezzanine segments in the set of mezzanine segments of the requested AVfile with at least one of an initial keyframe timestamp and a terminalkeyframe timestamp of each mezzanine segment in the subset of AVsegments occurring within a playback interval of the requested playbacksegment. Generally, the system identifies the mezzanine segments thatcoincide with or temporally overlap (based on timestamps) with arequested playback segment.

In one implementation, the system compares the timestamps of the initialkeyframe timestamp and the terminal keyframe timestamp of each mezzaninesegment to the playback interval of the playback segment to identifymezzanine segments that overlap with the playback segment. If either thestart or the end time of a mezzanine segment occurs between the startand end times of the playback segment, then the playback segmentincludes at least a portion of the mezzanine segment. In implementationsin which the mezzanine segments are stored without priming or trailingaudio buffers, the system can identify segments with starting timeswithin a trailing buffer's duration of the end of the playback intervaland/or segments with end times within a priming buffer's duration of thestart time of the playback interval. In this implementation, the systemensures that a priming buffer and/or a trailing buffer are included forthe playback segment.

Once the system identifies a set of consecutive mezzanine segmentscorresponding to a playback segment, the system can identify; whetherthe mezzanine segments have already been modified according to theassociated transcode-time script and transcoded into the requestedrendition; whether the mezzanine segments are currently being modifiedaccording to the associated transcode-time script and transcoded intothe requested rendition; or whether the mezzanine segments have alreadybeen modified and transcoded into the requested rendition and arepresent in the rendition cache.

If the system identifies that the mezzanine segments corresponding tothe playback segment have already been modified according to anassociated script and transcoded into the requested rendition, then thesystem can stream the resulting rendition segments to the requestingcomputational device directly from the rendition cache. Otherwise, thesystem can initiate the just-in-time editing and transcoding processdescribed below.

However, the system can identify mezzanine segments coincident with therequested playback segment in any other way.

7.1 Script Execution

Generally, the system can, in response to classifying a transcode-timescript as performant and in response to receiving a playback request,access the set of data inputs from the metadata store in Block S142.More specifically, the system can execute a transcode-time script thatimports a set of data inputs from the metadata store associated with theAV file via APIs defined by the system. Thus, the system can enable datatransfer between the local memory of a first computational device(within the system) executing the transcode-time script and a secondcomputational device that stores the metadata associated with thetranscode-time script.

In response to receiving a request to stream the AV file modified by thetranscode-time script at the URL associated with AV file and/orclassifying the transcode-time script as a performant script, the systemcan, for each frame of a set of mezzanine segments of the AV filecoinciding with the playback segment of the AV file, execute thetranscode-time script associated with the AV file to generate a modifiedframe, which together form a modified segment in Block S160. Thus, thesystem can execute graphical or audio modification of each video oraudio frame of the requested segments of the AV file. Because eachmezzanine segment of the AV file includes a keyframe for the subsequentframes within the mezzanine segment, the system can access the keyframeof each mezzanine segment in order to decode subsequent frames withinthe mezzanine segment prior to executing the transcode-time script onthe decoded subsequent frames. Additionally, the system can concurrentlydecode later frames within the segment, while executing thetranscode-time script on previously decoded frames, thereby reducing thelatency of the task. Thus, the system can apply modifications to the AVfile according to the transcode-time script on a frame-wise basis inorder to modify the AV file according to the transcode-time scriptassociated with the AV file.

As shown in FIG. 8A, in one implementation, the system executes thetranscode-time script on each frame (or on select frames according tothe transcode-time script) of each mezzanine segment corresponding tothe requested playback segment to generate a set of modified framesprior to just-in-time transcoding the output frames into the requestedrendition. Therefore, by executing the transcode-time script prior totranscoding the mezzanine segment into a rendition segment, the systemcan incorporate any modifications to the modified mezzanine segmentsmade by the transcode-time script into a rendition encoding of the AVfile.

In this implementation, the system can store an intermediate (modified)version of the AV file within the mezzanine cache in order to preventthe system from having to re-execute the transcode-time script on thesame set of frames in response to each request for these frames of theAV file. Thus, the system can: in response to classifying thetranscode-time script as performant and in response to receiving a firstplayback request, store a first modified frame of the AV file; andreceive a second playback request for the AV file from a secondcomputational device, the second playback request specifying a secondrendition of the AV file. Then the system can, in response toclassifying the first script as performant and in response to receivingthe second playback request: transcode the first modified frame of theAV file into the second rendition to generate a second output frame ofthe AV file; and transmit the second output frame to the secondcomputational device for playback at the second computational device.

As shown in FIG. 8B, in another implementation, the system can firsttranscode the set of mezzanine segments into the requested renditionsegments and then execute the transcode-time script on frames of therendition segments before reencoding the modified rendition segments. Inthis implementation, the system can potentially save processing time byexecuting the transcode-time script on the lower resolution and/or lowerbitrate rendition segments as opposed to the higher resolution and/orhigh bitrate mezzanine segments.

Therefore, upon executing the transcode-time script on either aconsecutive set of mezzanine segments corresponding to the playbacksegment or a consecutive set of rendition segments, the system generatesmodified output frames that comprise a set of consecutive modifiedsegments. The system can then transcode or reencode these modifiedsegments in order to prepare the modified segments for streaming.

7.2 Just-in-Time Transcoding

Generally, the system can transcode the output frames generated by thetranscode-time script into the first rendition. Alternatively, thesystem can reencode modified rendition segments in preparation forstreaming the modified rendition segments. More specifically, the systemcan transcode a modified frame of the AV file into the requestedrendition to generate an output frame of the AV file in Block S170.

The system can execute the just-in-time transcoding process described inU.S. patent application Ser. No. 16/458,630. Generally, in thejust-in-time transcoding process, the system can transcode mezzaninesegments coinciding with a requested playback segment into renditionsegments of the requested rendition in real-time upon receiving arequest from a CDN or AV player instance. Upon receiving a request for aplayback segment from a CDN or AV player instance, the system canidentify whether the corresponding mezzanine segments have not beenscheduled for transcoding, are currently being transcoded by the system,or have already been transcoded and the requested rendition segments arein the rendition cache. Based on this identification, the system caneither establish a peer-to-peer stream between the hardware that istranscoding the mezzanine segments and the requesting device or streamthe transcoded rendition segments directly from the rendition cache.

8. Cost Estimation

In one implementation, the system upon receiving a transcode-time scriptcan estimate the storage and computational costs of the transcode-timescript and/or associated metadata scripts and ingest-time scripts. Morespecifically, the system can: estimate a space of valid URL parametervalues based on the transcode-time script; estimate an audience of theAV file; and calculate a computational cost and/or a storage cost ofstreaming the AV file based on the space of valid URL parameter valuesand the audience of the AV file. Thus, the system can identify scriptsthat, when executed by the system, may tax available computational andstorage resources of the system and flag these scripts accordingly.Alternatively, the system can set a monetary price for executing a setof scripts associated with an AV file based on the estimatedcomputational costs and/or storage costs of executing the set ofscripts.

9. Runaway Script Detection

In one implementation, the system can detect transcode-time scriptsthat, when executed by the system, execute slower than real-time (i.e.,slower than the playback speed of the video), thereby introducingplayback delay at the AV player instance streaming the AV file. Morespecifically, the system can, in response to detecting execution of thetranscode-time script on the AV file and transcoding of the AV file intothe requested rendition is proceeding at slower than real-time, haltexecution of the transcode-time script. Thus, in applications in whichthe system has failed to identify a non-performant script via theaforementioned Blocks of the method S100, the system can identify slowerthan real-time performance of the transcode-time script and revert tojust-in-time transcoding and streaming the AV file without executing thetranscode-time script. The systems and methods described herein can beembodied and/or implemented at least in part as a machine configured toreceive a computer-readable medium storing computer-readableinstructions. The instructions can be executed by computer-executablecomponents integrated with the application, applet, host, server,network, website, communication service, communication interface,hardware/firmware/software elements of a user computer or mobile device,wristband, smartphone, or any suitable combination thereof. Othersystems and methods of the embodiment can be embodied and/or implementedat least in part as a machine configured to receive a computer-readablemedium storing computer-readable instructions. The instructions can beexecuted by computer-executable components integrated bycomputer-executable components integrated with apparatuses and networksof the type described above. The computer-readable medium can be storedon any suitable computer readable media such as RAMs, ROMs, flashmemory, EEPROMs, optical devices (CD or DVD), hard drives, floppydrives, or any suitable device. The computer-executable component can bea processor, but any suitable dedicated hardware device can(alternatively or additionally) execute the instructions.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the embodiments of the invention without departing fromthe scope of this invention as defined in the following claims.

I claim:
 1. A method comprising: receiving a first script: associatedwith a first audio-video file; and configured to modify the firstaudio-video file; calculating a first value of a performance metricbased on execution of the first script on a set of test files;classifying the first script as performant based on the first value ofthe performance metric; defining a metadata store associated with thefirst script and the first audio-video file and configured to comprise aset of data inputs; receiving a first playback request for the firstaudio-video file from a first computational device, the first playbackrequest specifying a first rendition of the first audio-video file; andin response to classifying the first script as performant and inresponse to receiving the first playback request: accessing the set ofdata inputs from the metadata store; executing the first script on aframe of the first audio-video file based on the set of data inputs togenerate a first modified frame of the first audio-video file;transcoding the first modified frame of the first audio-video file intothe first rendition to generate a first output frame of the firstaudio-video file; and transmitting the first output frame of the firstaudio-video file to the first computational device for playback at thefirst computational device.
 2. The method of claim 1, furthercomprising: receiving a second script: associated with the firstaudio-video file and the first script; and configured to generate theset of data inputs from the first audio-video file; and at ingest timeof the first audio-video file: executing the second script on the firstaudio-video file to generate the set of data inputs; and storing the setof data inputs in the metadata store associated with the first script.3. The method of claim 1, further comprising: receiving a second script:associated with the first audio-video file and the first script; andconfigured to update the set of data inputs based on a third-party datasource; and after ingest time of the first audio-video file,periodically: executing the second script to retrieve new values for theset of data inputs from the third-party data source; and updating theset of data inputs in the metadata store to generate an updated set ofdata inputs based on the new values for the set of data inputs.
 4. Themethod of claim 3, further comprising: receiving a second playbackrequest for the first audio-video from a second computational device,the second playback request specifying the rendition of the firstaudio-video file; and in response to classifying the first script asperformant and in response to receiving the second playback request:accessing the updated set of data inputs from the metadata store;executing the first script on the frame of the audio-video file based onthe updated set of data inputs to generate a second modified frame ofthe first audio-video file; transcoding the second modified frame of thefirst audio-video file into the first rendition to generate a secondoutput frame of the first audio-video file; and transmitting the secondoutput frame of the first audio-video file to the second computationaldevice for playback at the second computational device.
 5. The method ofclaim 1: further comprising assigning a URL to a combination of thefirst script and the first audio-video file; and wherein receiving thefirst playback request for the first audio-video file from the firstcomputational device comprises receiving the first playback request forthe first audio-video file from the first computational device via theURL, the first playback request specifying a first rendition of thefirst audio-video file.
 6. The method of claim 5: wherein assigning theURL to the combination of the first script and the first audio-videofile comprises assigning the URL to the combination of the first scriptand the first audio-video file, the URL comprising a URL parameterfield; further comprising, extracting a URL parameter value from the URLparameter field; and wherein executing the first script on the frame ofthe first audio-video file based on the set of data inputs to generatethe first modified frame of the first audio-video file comprisesexecuting the first script on the frame of the first audio-video filebased on the set of data inputs and the URL parameter value to generatethe first modified frame of the first audio-video file.
 7. The method ofclaim 6, further comprising: estimating a space of valid URL parametervalues based on the first script; estimating an audience of the firstaudio-video file; and calculating a computational cost of streaming thefirst audio-video file based on the space of valid URL parameter valuesand the audience of the first audio-video file.
 8. The method of claim6, wherein executing the first script on the frame of the firstaudio-video file based on the set of data inputs and the URL parametervalue to generate the first modified frame of the first audio-video filecomprises rendering a watermark representing the URL parameter valueover the frame of the first audio-video file to generate the firstmodified frame of the first audio-video file.
 9. The method of claim 1,further comprising, in response to detecting that execution of the firstscript on the first audio-video file and detecting that transcoding ofthe first audio-video file into the first rendition is proceeding atslower than real-time, halting execution of the first script.
 10. Themethod of claim 1 further comprising: in response to classifying thefirst script as performant and in response to receiving the firstplayback request, storing the first modified frame of the firstaudio-video file; receiving a second playback request for the firstaudio-video file from a second computational device, the second playbackrequest specifying a second rendition of the first audio-video file; andin response to classifying the first script as performant and inresponse to receiving the second playback request: transcoding the firstmodified frame of the first audio-video file into the second renditionto generate a second output frame of the first audio-video file; andtransmitting the second output frame to the second computational devicefor playback at the second computational device.
 11. The method of claim1, wherein calculating the first value of the performance metric basedon execution of the first script on the set of test files comprises: foreach test file in the set of test files calculating a runtime forexecution of the first script on the test file; and calculating thefirst value of the performance metric as a summary metric of the runtimefor each test file in the set of test files.
 12. The method of claim 1,wherein calculating the first value of the performance metric based onexecution of the first script on the set of test files comprises:selecting a set of similar test files to the first audio-video filebased on the audio-video file and a video classification model; andcalculating the first value of the performance metric based on executionof the first script on the set of similar test files.
 13. The method ofclaim 1, wherein calculating the first value of the performance metricbased on execution of the first script on the set of test filescomprises: selecting a set of similar test files to the firstaudio-video file based on a prior set of files sharing a publisher withthe first audio-video file; and calculating the first value of theperformance metric based on execution of the first script on the set ofsimilar test files.
 14. The method of claim 1: wherein calculating thefirst value of the performance metric based on execution of the firstscript on the set of test files comprises: calculating the first valueof the performance metric based on execution of the first script on theset of test files via a central processing unit; and calculating asecond value of the performance metric based on execution of the firstscript on the set of test files via a graphics processing unit; whereinclassifying the first script as performant based on the first value ofthe performance metric comprises classifying the first script asperformance based on a first value of the performance metric from thefirst value of the performance metric and the second value of theperformance metric; further comprising, selecting a target processingunit, from the central processing unit and the graphics processing unit,to execute the first script, the target processing unit characterized bya minimum value of the performance metric from the first value and thesecond value; and wherein executing the first script on the frame of thefirst audio-video file based on the set of data inputs to generate thefirst modified frame of the first audio-video file comprises executingthe first script on the frame of the first audio-video file based on theset of data inputs to generate the first modified frame of the firstaudio-video file via the target processing unit.
 15. The method of claim1, further comprising: receiving a second script: associated with asecond audio-video file; and configured to modify the second audio-videofile; calculating a second value of the performance metric based onexecution of the second script on a second set of test files;classifying the second script as non-performant based on the secondvalue of the performance metric; and in response to classifying thesecond script as non-performant, for a frame of the second audio-videofile and at ingest time of the second audio-video file: executing thesecond script on the frame of the second audio-video file to generate anoutput frame of the second audio-video file; and storing the outputframe of the second audio-video file.
 16. A method comprising: receivinga first script: associated with a first audio-video file; and configuredto modify the first audio-video file; calculating a first value of aperformance metric based on execution of the first script on a set oftest files; classifying the first script as performant based on thefirst value of the performance metric; receiving a first playbackrequest for the first audio-video file from a first computationaldevice, the first playback request specifying a first rendition of theaudio-video file; and in response to classifying the first script asperformant and in response to receiving the first playback request:executing the first script on a frame of the first audio-video file togenerate a modified frame of the first audio-video file; transcoding themodified frame of the first audio-video file into the first rendition togenerate an output frame of the first audio-video file; and transmittingthe output frame of the first audio-video file to the firstcomputational device for playback at the first computational device. 17.The method of claim 16: further comprising: defining a metadata storeassociated with the first script and the first audio-video file andconfigured to comprise a set of data inputs; and in response toclassifying the first script as performant and in response to receivingthe first playback request, accessing the set of data inputs from themetadata store; and wherein executing the first script on the frame ofthe first audio-video file to generate the modified frame of the firstaudio-video file comprises executing the first script on the frame ofthe first audio-video file based on the set of data inputs to generatethe first modified frame of the first audio-video file.
 18. The methodof claim 16, further comprising: receiving a second script: associatedwith a second audio-video file; and configured to modify the secondaudio-video file; calculating a second value of the performance metricbased on execution of the second script on a second set of test files;classifying the second script as non-performant based on the secondvalue of the performance metric; and in response to classifying thesecond script as non-performant, for a frame of the second audio-videofile and at ingest time of the second audio-video file: executing thesecond script on the frame of the second audio-video file to generate anoutput frame of the second audio-video file; and storing the outputframe of the second audio-video file.
 19. A method comprising: receivinga first script: associated with a class of audio-video files; andconfigured to modify audio-video files in the class of audio-videofiles; calculating a first value of a performance metric based onexecution of the first script on a set of test files; classifying thefirst script as performant based on the first value of the performancemetric; defining a metadata store associated with the first script andthe class of audio-video files and configured to comprise a set of datainputs; receiving a first playback request for an audio-video file inthe class of audio-video files from a first computational device, thefirst playback request specifying a first rendition of the audio-videofile; and in response to classifying the first script as performant andin response to receiving the first playback request: accessing the setof data inputs from the metadata store; executing the first script on aframe of the audio-video file based on the set of data inputs togenerate a first modified frame of the first audio-video file;transcoding the first modified frame of the first audio-video file intothe first rendition to generate a first output frame of the firstaudio-video file; and transmitting the first output frame of theaudio-video file to the first computational device for playback at thefirst computational device.
 20. The method of claim 19, whereinreceiving the first script comprises receiving the first script:associated with the class of audio-video files comprising a set ofaudio-video files from one entity; and configured to modify the class ofaudio-video files.